Hydraulic press



Sept. 29, 1936.- w. A. WI'LHELM k 2,055,831

HYDRAUL I C PRE S S Original Filed Aug. 11, 1930 7 Sheets-Sheet l WITNESSES INVENTOR WA; WZ'ZbeZm,

BY M ii? ATTO W wa Sept. 29, 1936.

w. A. WILHELM v HYDRAULIC PRESS Original Filed Aug. 1 1930" 7 Sheets-Sheet 2 WITNESSES 6 NvENToR 9 TViZhelm ATTORN EYS Spt.29, 1936. AWILHELM 2,055,831

" HYDRAULIC PRESS Original Filed Aug. 11, 1930 7 sheets-sh? 3 lNVENTOR WA- ll fllivelm,

BvY

ATTORNEYv Sept. 29, 1936.

w. A. WlLHELM 2,055,831

HYDRAULIC PRESS Original Filed Aug. 11, 1930 7 Sheets-Sheet 4 7 m' 1 I WITNESS s h TA.WzZh e m V BY J ATTORNEYS Sept. 29, 1936. w A W|LHELM 2,055,831

HYDRAUL I C PRE S S Original Filed Aug. 11, 1930 7 Sheets-Sheet 5' WITNESSES I WA Q E EOR z e m, i 'H ATTORNE S Sept. 29, 1936.

w. A. WILHELM 2,055,831

HYDRAULIC PRESS Original Filed Aug. 11, 1930 '7 Sheets-Sheet 6 INVENTOR 'WAjl zlbelm ATTORNEY WITNESSES se yze, 1936. w EL 2,055,831-

- HYDRAULIC PRESS O rigi nal Filed Aug. 11, 1930 7 Sheets-Sheet 7 ACCUMULATOR INVENTOR WA. fiilbelm Q, BY MW,

ATTORNEY WITNESSES PUMP TANK Patented Sept. 29, 1936 UNITED STATES PATENT OFFICE HYDRAULIC PRESS Wilson A. Wilhelm, Vernon, Tex.

4 Claims.

This invention relates to improvements in hydraulic presses, and its objects are as follow:- 7

First, to provide a hydraulic motor which is 5 especially adapted to the requirements of the press disclosed in an application for patent by Wilson A. Wilhelm, filed August 11, 1930, Serial No. 474,602 of which this application is a division, the parent application having since eventu- 10 ated in Patent No. 1,973,786 of September 18,

' Second, to operate the motor on a progressive power principle, in other words to start it under low fluid pressure in all of its cylinders, then 15 continue its operation under high pressure in some of its cylinders and finally complete its operation under high pressure in all cylinders, this in order to apply a steadily increasing pressure to the ram block and so to the press.

20 Third, to confine the actionof the low and high pressure cylinders and rams to the closing of the press for the purpose of squeezing the liquid out of liquid-bearing material, but to use the reversing cylinders and rams both for opening 25 the press as part of the normal operation and to close the press (without liquid-bearing material being therein) so as to gain access to the low and high pressure cylinder rams.

Fourth, to provide the separate reversing cylin- 30 ders and rams for opening the press and driving the press rams back into their cylinders thereby simultaneously returning the inactive fluid to the accumulator.

Fifth, to employ the rams of the reversing cylinders for the purpose of receding the ram block from the motor cylinder block, thereby closing the press boxes and exposing the ends of the press rams for removal and consequent access to their crimps.

Sixth, to provide an accumulator as the reservoir of a large volume of low-pressure fluid, from which accumulator the low-pressure fluid is initially conducted to the low-pressure cylinders of the press, the intervening action of a highpressure pump being confined to building up a high pressure on a relatively small volume of fluid which is eventually supplied to the highpressure cylinders and simultaneously imposed on the fluid already in the low-pressure cylinder.

50 Seventh, to provide a pair of valves (382 and 383) in the pressure-fluid system, each automatically operable respectively at maximum accumulator pressure during the filling of the low-pressure cylinders thereby to release the high-pres- 55 sure fluid to the auxiliary or high pressure cylinders, and to release the high-pressure fluid for imposition on the fluid already in the low-pressure cylinders thus to work the various rams under a universally high pressure.

Eighth, to provide a control valve mechanism 5 of which the foregoing valves are a part, the manual operation of said mechanism initiating the automatic action of the valves in time.

In the drawings:

Figure 1 is a front elevation of the hydraulic motor, its specific application being to the press of the foregoing patent, the press being fragmentarily shown.

Figure 2 is a plan view of the motor cylinders, the shafts or vertical rams of a certain cake stripper with which this application is not concerned being shown in section.

Figure 3 is a cross section of the motor taken on the line 3-3 of Figure 1.

Figure 4 is a left end elevation of the motor.

Figure 5 is a vertical longitudinal section taken on the line 5-5 of. Figure 2, particularly illustrating the main cylinders of the cylinder block.

Figure 6 is a horizontal section taken on the line 6-6 of Figure 4.

Figure 7 is a side elevation of the ram block, the view appearing as seen by an observer from a position opposite to that of Figure 1.

Figure 8 is a vertical cross section taken on the line 8-8 of Figure 1, particularly illustrating that face of the ram block confronting the hydraulic motor.

Figure 9 is a horizontal section taken on the line 99 of Figure 4, particularly illustrating one of the auxiliary and reverse cylinders.

Figure 10 is a perspective view of. the valve for controlling the operation of the motor, hence the opening and closing of the press.

Figure 11 is a diagram particularly illustrating the port connections of the poppet valves. Figure 12 is a diagram of the motor control valve and its connections with the main, auxiliary and reverse cylinders of the hydraulic motor.

Figure 13 is a detail section taken on the line l3l3 of Fig. 1.

According to the instant disclosure, the hydraulic motor is especially adapted to perform the functions of the foregoing patent. It is conceivable, however, that it may be put to other uses which require first the universal application of a low pressure, second the concentrated application of. a relatively high pressure at selected points, and third the universal application of the same relatively high pressure.

It is repeated that the motor is particularly of meal and cut ofi the surplus, whereupon the press is telescoped to extract the oil. Upon a later opening of the press a stripper (not shown) is brought into position over the press to strip the cakes from the press cloths and remove the cakes from the press for subsequent disposal.

It is the instant hydraulic motor which'telescopes and opens the press. Its main aspects are the cylinder block I (Fig. 1) with its reverse cylinders 2, 3 (Figs. 3 and 4) and its rams 4- (Fig. 5) and the ram block 5 (Figs. 1 and 8). Associated with this motor are the head block 5 (Fig; l), the press boxes 1 and the double entering'heads I0, all of the press. The respective functions of the motor are controlled by the valve mechanism I2 (Figs. 10 and 12) The cylinder block I comprises a casting (Fig. 3) in which a pair of main cylinders [1, I8 is combined with auxiliary cylinders i9, 20. The act of compression which occurs by the telescopihgof the entering heads I into the press boxes approximately 14 to 6".

I'isaccomplished by the initial introduction of fluid at a relatively low pressure into each of the cylinders I1, I8, I9 and 20, then at a relatively high pressure into cylinders I 9, 20, and finally at said relatively high pressure also into the cylinders I'I,"l8 so that the compressing operation is finished at the last high pressure.

There is thus a stage-application of. fluid pressure. While the gradual application of the pressure'is' a desirable result yet the outstanding advantage of an initial high-volume low-pressure application of the fluid is an avoidance of the sudden draining and dropping in pressure of the hydraulic system. This can be better understood 1 by considering Figure 12 which comes under the head of the control valve mechanism. I

Here is an accumulator 2| in which a fluid pressure head is built upduring the reversal of the press. The working low pressure arbitrarily selected is 50 lbs. per square inch, although this may be more or less in practice. If the large volume of fluid demanded of the accumulator 2| for initial introduction into the cylinders I I to 20 (Fig. 3) were required to be applied by the high pressure pump 22, (Fig. 12) the latter by virtue of its inherent nature would be unable tobuild up the requisite pressure behind the large volume of fluid quickly enough to suit the requirement of speed.

So by abstracting a relatively large volume of fluid from the accumulator 2| at the beginning of compression with a consequent initial filling of the cylinders I! to 20 (Fig. 3) the subsequent working of the pump 22 (Fig. 12) will be confined solely to the building up of the pressure and none of its strokes need be wasted in merely charging the cylinders with fluid. Toward these ends the cylinders I'I, I8 (Fig. 3) are made larger in diameter than the cylinders I9, 20, the ratio being 'All ofthe cylinders I'I, I8 (Fig. and I9, 20 (Fig. 3) are approximately the same length, being open at the ends nearest the press boxes I and closed at the other ends; The cylinders are stationary while the rams 4 are movable in the horizontal direction to telescope the entering heads and press or receiving boxes I. The main cylinders I], I8 are of the same size and are located with their axes in the same vertical plane and on the vertical center line of the press. This has a purpose. The press boxes I are vertically elongated to produce a cake 25 of the shape in dotted lines in Figure 3, so by disposing the cylinders I'I, I8 one above the other the greatest amount of pressure can be applied to the stock and to the cake. If the arrangement were otherwise the' thrust area of the upper and lower rams 4 (Fig. 3) would overlap the extremities oi. the cake to a far greater extent than shown.

The auxiliary cylinders i9, 20 are also of the same size, but as previously indicated are smaller in diameter than the cylinders I'I, I8. The particular grouping of the cylinders disclosed makes it possible to locate the smaller cylinders in the recesses occurring at the sides of the larger cylinders, enabling a sturdy and compact form. The symmetrical disposition of the cylinders also enables a more uniform application of the pressure, although an outstanding reason for dividing the application of pressure among four cylinders rather than among a lesser number, is to avoid the making and machining of larger masses of metal as well as to avoid the possibility of running into imperfect portions of hide from which certain crimps 23, 24 (Figs. 5 and 9) are made. A large band or heavy flange-like projection 26' (Figs. 2 and 5)substantially encircles the open 'end of the cylinder'block I Fairs of press columns 29, 38 (Figs. 1 and 8), respectively at the front and rear of the press, fixedly but ad; justably connect the cylinderblock (making use of the band 26) with the head block 6 accord ing to What is known as either a short or long hitch. The structural details of these columns and their hitches are described and claimed in Patent No. 1,973,786. A smaller band 33 is provided at theleft end of the cylinder block (Figs. 2 and 9). 'Ihe'bands 26, 33 practically surround the whole group of cylinders IT to 20, and their particular purpose is to strengthen and reinforce the cylinders respectively at the open end where the band 26 obviates the tendency to break out the metal should the rams 4 commence to gyrate, and to reinforce the cylinders at the points where the side walls unite with the left end w'alliFig. 5).

The reverse cylinders 2, 3 are stationed at the front and rear of the cylinder block I (Fig. 2), being held in place by clips 4'! or their equivalents and terminal blocks 48 which are made to constitute the heads of the reverse cylinders (Fig. 9)". The opposite ends of the cylinders are closed by caps 49. These are bridged by a manifold 50 (Fig. 2) respectively with inlet and exhaust'valves 52 and. 53 (Fig. l). The valve 52 will be open to pressure only when it is desired to closethe press in order to recede the ram block 5 (Fig. 5) from the cylinder block I thus to make the exposed ends of the rams 4 (Figs 3 and 5) accessible for the purpose of removing the crimps 23, 24.

In the ordinary operation of the press the sole purpose of the reverse cylinders 2, 3 is to open or separate the press box and double entering head units 1, ID. troducing pressure fluid into the right ends of the cylinders 2, 3 through ports 65 which have communication with the cylinders through the e g eel lesk, (F ande g nneq e by This is accomplished by ina manifold 66 (Fig. 12) for an equal supply of fluid. Pressure thus applied for the opening of the press is also applied to the right ends of the rams 4 (Figs. 5 and 9) by means of the ram block 5, thereby driving them back in their cylinders I1, l8 and I9, 29 (Fig. 3)'and causing the pressure fluid to return to the accumulator 2| (Fig. 12)

The reverse cylinders are, therefore, the means for opening the press and returning the inactive or residual fluid to the accumulator. When pressure is applied to the rams 4 for the closing of the press, or the performance of the act of extraction, an escape of fluid ahead of the reverse pistons 54 (Fig. 9) occurs to an open pump tank 61 (Fig. 12) by way of the control valve mechanism 12 to be described later.

Heretofore, the rams 4 of the cylinders l1, l8, l9 and 29 (Fig. 3) have been referred to in a general way because of the collective function that they perform in acting against the ram block 5 (Figs. 5 and 9) in closing the press. However, the rams of the main cylinders l1, l8 and auxiliary I9, 20 have allied structural differences which are explained thus:-

Taking the rams 4 of the main cylinders l1, l8 first, it is to be observed (Fig. 5) that each has a recess 68 in the leading end to receive a corresponding boss 59 on an extension which is diametrically reduced to match the smallest diameter of a peripheral bevel H on the leading edge. The purpose of this bevel is to uniformly expand the inner component of the crimp 23, immediately following the renewal of the crimp prior to which the respective ram was moved back to the limit in the main cylinder.

The extension I9 is secured to its ram by means of stud bolts 12, the nuts 13 of which are sunk in a recess 14 so that the outermost ones.

will at most be flush with the working surface of the flanged end 15. The flange 15 limits the inward movement of its ram 4 in respect to the main cylinder. This being the case, it is to be observed that the line of demarcation between the ram and its extension 10 is well forward of the position of the crimp 23.

There is never any possibility of the edges of the crimp 23 becoming burred by the passage of the dividing line over its inner component. In addition to the advantage which the position of the division line between the ram and its extension 10 has in respect to the crimp 23 a more important advantage follows. The specific arrangement is disclosed in Figure 5.

This has to do with the renewal of the crimp 23. Renewals are comparatively rare, but they must be made at times. Under such circumstances temporary use will be made of the reverse cylinders 2, 3 to close the press as brought out before, in order to drive the ram block 5 (Fig. 5) clear of the working faces of the extensions 10. There is now ample room for the operator to work between the extensions 10 and the ram block 5 to remove the nuts 13 (Fig. 5) and pull each extension 10 away from' the ram 4.

The ram 4 is left in its respective main cylinder and is pushed all the way so that the leading end clears the crimp 23. The space 16 (Fig. 5) between the inner ends of the main cylinder and ram is provided for this purpose. Upon the replacement of the old crimp with a new one the operator will simply pull the ram 4 forwardly by taking hold of the stud bolts 12. The bevel ll makes a smooth passage of, the

leading end through the new crimp 23 without injury to-the edges. The extension 10 is now replaced and the nuts 13 screwed home.

In addition to matching the smallest diameter of the bevel II the reduction in diameter of the extension 70 from that of the ram 4 has the rather important advantage of obviating the possibility of damaging the inner edges of the extensions by virtue of contact with the right edge of the main cylinder should there be any slight misalinement of the stud bolts 12 or a possible inadvertent shifting of the extension in putting it back on the stud bolts. In other words, the diametral reduction of the extension 10 well avoids the cylinder wall so that should there be any slight portion overlapping the leading edge of the ram there will be no possibility of its hanging against the edge of the cylinder on the inner movement of the ram during an opening of the press.

There is a similarity in the rams 4 of the smaller and auxiliary cylinders I9, (Fig. 9). The leading end of each of these rams is bevelled at 11in order to pass the crimp 24 without damage under a circumstance similar to that already mentioned. This end of the ram is tapped at 18, or made with some equivalent provision, for the application of an implement by which to pull the ram outwardly after renewing the crimp. It will be understood that for such purpose the ram has to be pushed back in the space 19 so that the leading end clears the crimp 24 for access.

From this it will be understood that the rams 4 have only to be pushed back in the respective cylinders in order to renew the crimns 23. 24. bearing in mind of course that in the instance of the main ram it is first necessary to remove the extensions in (Fig. 5). This simple performance can be accomplished in a very short time and distinguished from the laborious and hazardous operation of renewing crimps in known presses of this type which necessitates not only the removal of the ram and ramblock but the jacking up of all of the boxes and possib-ly the removal thereof from the press.

The ram block 5 is that element of the press through which the working thrust of the main and auxiliary rams 4 (Figs. 5 and 9) is transmitted to the stock through the successive entering heads l0 and press boxes I for an extraction of the oil. The ram block is shaped (Fig. 8) to provide full bearing surfaces for the right ends of the rams. The horizontal, auxiliary rams 4 which work in positions quite beyond the front and rear edges of the cake 25 (Fig. 3), exert their thrust on a reinforcing cross rib 89 (Fig. 8). All of the pressure is concentrated on the ram block 5 and transmitted thereby as already pointed out.

The cars 63 with which the reverse piston rods 51 are connected by means of a ball-faced nut 59 and a jamb nut 58 (Fig. 9) are reinforced by webs 8| (Fig. 8) which combine with brackets 82 in the square holes 83 of which the shanks 84 of roller forks 85 are secured. The square holes 83 are so placed that the corners ofthe verse leveling of the ram block 5. A lock nut 93 on the reduced threaded end 94 of the shank secures the adjustments.

On the working face I89 of the ram block 5, (Fig. 2), that is to say, the face next to the first or adjacent press box 1 (Fig. 1), there is a pad IIO (Figs. 2 and '1) across the upper edge of which there is a formation of hinge knuckles III which support a drainage head II2 described in detail in the patent. The head block 6 occupies a position at the right extremity of the press (Fig. 1) in confronting relationship to the ram block 5. Thus far it will be understood that it is the motion of the ram block 5 to the right by action of the hydraulic motor that telescopes the press, in other words the press boxes 1 and entering heads I6, for the extraction of the oil. Of necessity the head block 6 must be stationary in order to act as an abutment for the press boxes and entering heads. To the latter end the head block 6 provides an anchorage for the right ends of the columns 29, 30. Thus the press is rigidly secured to withstand the pressure set up between the cylinder block I and head block 6.

The control valve mechanism I2 enables the operator to close and open the press from a safe distance. As brought out earlier in this description, the functions of the control valve mechanism are to fill both pairs of main and auxiliary cylinders I1, I8 and I9, 28 (Fig. 3) with fluid under an initial comparatively low pressure, then follow this with the application of fluid under a comparatively high pressure to the auxiliary cylinders I9, 28, while retaining the initial low pressure in the main cylinders I1, I8, finally applying said high pressure to all of the cylinders. It is also by means of this valve mechanism that pressure fluid is admitted to the reverse cylinders 2, 3 (Figs. 2 and 9) for the socalled opening of the press.

All of the foregoing changes of pressure and directions of the press are accomplished by the movement of the single control lever 335 (Fig. 10) of the main control valve generally designated I2. This control valve has eight doubleported, balanced, spring-loaded poppet valves 336, 331, 338, 339, 348, SM, 342 and 343, the valve members 3440f which are capable of being opened by the push of levers 345, 346, 341, 348, 349, 358, 35I, and 352- by the action thereagainst of cams on a lay shaft 353 to which the foregoing control lever 335 is attached.

Figure 12 is in part a diagrammatic development of the control valve I2. Although the lay shaft 353 appears four times this is to be regarded as the same shaft. The cams 35.4, 355 are for the operation of the levers 345, 346 and are identical with cams 356, 351 for the operation of the levers 341, 348. These cams are spaced at 358, 359 so that a turn of the shaft 353 in one direction will not affect one pair of the levers for example 346, 348, while one pair of the cams, for example 354, 356 raises the. companion levers 345, 341.

In the instance of the valves 348, 34I the cams 360, 36I are spaced as at 362.. The cam 360 comprises a blunt-pointed lobe while the cam 36 I has a relatively long face. The co-acting lever 350 of the latter has a hook end which is best adapmd to maintaining the valve member 344 of the respective poppet valve 341 open while the lever 335 assumes the neutral position as well as when said lever is moved to the left (Fig. 10). or closing position of the press.

The levers 35I, 352 are also of the hook-end type, these being acted on by a single cam 363 in the nature of a blunt-ended lobe. This cam is adapted to hold the valve members 344 of both poppet valves 342, 343 open when the lever 335 assumes the neutral position (Fig. 10) and to close these valve members when the lever 335 is shifted either to the left or right respectively for the closing of the press or reversal and opening thereof.

In the neutral position of the valve lever 335 (Fig. 10) all of the main I1, I8, auxiliary, I9, 20 and reverse cylinders 2, 3 are opened to the pump tank 61 (Fig. 12) by virtue of the poppet valves (MI, 342 and 343 being opened. The purpose of this provision is to relieve these cylinders of pressure. The conduits by which the main and auxiliary cylinders are interconnected at times and by which each of the various cylinders is connected with the poppet valves are described as follows:-A conduit 364 (Fig. 12) joins a branch 365 that in turn has common communication with ports 366 (Fig. 5) of the main cylinders I1, I8. This conduit has a lateral 361 which terminates at the poppet valve 340 which, in turn, has a connection 368 with the poppet valve 342. That valve has a pipe 369 discharging into the pump tank 61.

The continuation of the conduit 364 embraces a check valve 310 and terminates at the poppet valve 339, there being a branch 31I from this continuation that ultimately connects with a branch 312 commonly joining the ports 313 of the auxiliary cylinders I9, 20 (Fig. 9). The branch 31I contains a back check valve 314 and has a lateral 315 communicating by way of a branch 316 with the poppet valve 343 and by way of a branch 311 with the poppet valve 338.

The branch 31I also has connections 318 and 319 respectively with a low pressure cylinder 380 and a lateral 38I which terminates at balanced valves 382, 383 and has a connection at 384 with a high pressure cylinder 385.

Branches 386, 381 connect the valves 382, 383 respectively with the poppet valve 331 and the conduit 364. A conduit 388 connects the poppet valves 336, 34| and has a branch 389 leading to the previously described manifold 66 of the reverse cylinders 2, 3.

Fluid under a comparatively low pressure is supplied to the control valve mechanism by the accumulator 2| through a conduit 390 which communicates with the poppet valve 340. The previously described high pressure pump 22 has a connection at 39! with the poppet valve 336. Ports 392, 393 and 394 connect the respective pairs of the poppet valves 336, 331; 388, 339 and 342, 343. The general arrangement is shown both in Figures 11 and 12. A connection 395 joins the valves 34I, 343 while a connection 396 joins valves 338, 346.

There are only three positions of the control lever 335 (Fig. 10) namely, neutral, closing and reverse or opening. These terms have reference to the action of the press. Assume the press boxes 1 to have been filled with stock and closed. The lever 335 will be moved to the left. The corresponding turning of the lay shaft 353 to the left will cause the opening of valves 331 and 339, leaving the valve 34I open and closing valves 342, 343. These actions are accomplished by the raising movements of the cams 355, 351 against the levers 346, 348, the long face of the cam 36I and the displacement of the cam 363 from beneath both levers 35I, 352.

Fluid then flows under low pressure (approximately 50 lbs.) from the accumulator 2!, through conduit 399 to valve 349, (closed), thence by way of connection 396 to valve 338 (closed), through port 393 to valve 339 (open), past check valve 319 into conduit 364 to the branch or manifold 365 and from there into each of the main cylinders I1, I8. A division of the fluid flow occurs in the branch 31! past the check valve 314, reaching the connection or manifold 312 and from there flowing into the auxiliary cylinders I9, 29. Each of these cylinders is thus initially filled with fluid under an initially low pressure.

The valve members of the respective valves 382, 383 are connected with pistons 391, 398 in the cylinders 389, 385 where they are pressed against by springs 399, 499 respectively designed to yield at approximately 50 lbs. and 3800 lbs. per sq. in. on the opposite sides of the pistons. A portion of the fluid flowing to the auxiliary cylinders I9, 29 by way of the branch 31! is diverted to the cylinder 38!) through the connection 318.

When the maximum low pressure is built up against the left side of the piston 391 so that the spring 399 is overcome there will be an opening of the valve 382 with a consequent admission of fluid under high pressure to the auxiliary cylinders I9, 29 by way of the connection 39!, valve 336 (closed), port 392, valve 331 (open), branch 396, valve 382, lateral 38!, connection 319, branch 31! to the connection or manifold 312.

Now there is the condition of high pressure fluid being supplied to the auxiliary cylinders I9, 29 while low pressure is still maintained in the main cylinders I1, I8. As the. high pressure builds up against the left side of piston 398 the ultimate overcoming of the spring 499 will open the valve 383 so that there will be a division of the flow of the high pressure fluid into the branch 381 and conduit 354, whence it passes to the connection or manifold 365 to also fill the main cylinders I1, I8 with high pressure fluid. Thus all four cylinders are filled with high pressure fluid to impose maximum pressure on the stock in the press.

During the foregoing forward action of the press the residue of the reverse cylinders 2, 3 was discharged by the movement of the pistons 54 to the right (Fig. 9) with the ram block 5, the flow occurring through manifold 66 (Fig. 12), branch 389, conduit 388, valve 34!, connection 395, around closed valve 343, through port 394 and through pipe 369 to the pump tank 61.

The foregoing pressure on the press is maintained as long as the control lever 355 remains in the left hand position. When it is shifted to the central or neutral position there will be an instant relaxation of the pressure in the main and auxiliary cylinders by virtue of the opening of the valves 34!, 342 and 343 as shown in Figure 12 and as previously described. The next act is to reverse or open the press, and insofar as the retraction of the entering heads I9 from the press boxes 1 is concerned the function of the valve mechanism I2 is as follows:-

A shifting of the control lever 335 to the right will turn the lay shaft 353 to the right whereupon valves 336, 338 and 349 will open while valves 331, 339 will be permitted to remain closed, valves 34!, 342 and 343 being moved to closed positions by the departure of cams 36! and 363 from beneath the ends of levers 359, and 352.

The maximum 3800 lb. pressure of the pump 22 (Fig. 12) is now delivered to the right ends (Fig. 9) of the reverse cylinders 2, 3 by way of connection 39! (Fig. 12) open valve 336, conduit 388, branch 389 and manifold 68 which terminates at the ports 65. The result is a quick retraction of the entering heads I9 from the press boxes 1.

The opening pressure of the press is thus exerted against the right ends of the rams 4 both in the main and auxiliary cylinders I1, I8 and I9, 29. The fluid from the main cylinders is thus returned to the accumulator 2! by way of manifold 365, conduit 364, lateral 361, open valve 349 and conduit 399. Similarly, the fluid from the auxiliary cylinders I9, 29 is returned to the accumulator 2! by way of manifold 312, lateral 315, open valve 338, connection 398, valve 349 and conduit 399. The returning rams thus serve to charge the accumulator 2! in readiness for its next low pressure function. a

The operation although heretofore described in considerable detail is now briefly reviewed here. The press of the patent includes the press box and entering head units 1, I9, these elements occurring in alternation as suggested by Figure 1. These units are capable of movement away from and toward each other with an opening and closing or telescopic action which occurs between the fixedly mounted cylinder block I on one hand and the head block 6 on the other hand. As already pointed out it is the function of the hydraulic motor to do the opening and closing.

Assume, first, that all of the compartments of the press have been filled with a liquid-bearing substance. After closing the boundaries of the press boxes the control lever 335 (Fig. 10) of the valve mechanism I2 is moved to the left according to the arrow marked closing.

Comparatively low pressure fluid is simultaneously admitted to the main and auxiliary cy1-- inders I1, I8 and I9, 29 (Figs. 3, 5 and 12). This fluid is supplied by the accumulator 2! and traverses the conduit 399, connection 396 and conduit 364, there being a division of the fluid into the branch 31!. All of the rams 4 move forwardly or to the right withone accord. They act simultaneously on the ram block 5, and the action is to begin closing the entering heads I9 in all of the press boxes 1.

The material will yield a little in each of the press box compartments so that the initial compression will be made evident from one end to the other of the press. When the initial pressure has had its full effect then the fluid under comparatively high pressure is admitted to the auxiliary cylinders I9, 29 and finally to the main cylinders I1, I8 also.

This is accomplished by a building up of a maximum low pressure against the piston 391 (Fig. 12) which upon receding opens the valve 382 for an admission of high pressure fluid from the pump 22 to the branch 31!. High pressure fluid is thus admitted to the auxiliary cylinders I9, 29. The low pressure fluid is maintained in the main cylinders I1, I8. When maximum high pressure is built up against the piston 398 (Fig. 12), the consequent opening of the valve 383 admits high pressure to the main cylinders I1, I8 also by way of the branch 381 and conduit 364.

Pressure is thus applied to the stock. This application is gradual and progressive. The various pressure values are applied in stages. Thus there is a gradual extraction of the oil, and as this filters through the press cloths (not shown) it runs down and out at the bottom of the press. Separation of the press box and entering head units must occur in time, and this is accomplished by moving the control lever 335 (Fig. 10) to the right as indicated by the arrows designated reverse or open.

Fluid is then admitted under high pressure to the right ends of the reverse cylinders 2, 3 (Figs. 3 and 9). This draws the ram block 5 back and all of the press boxes! and entering heads ID with it. The pressed cakes 25 (Fig. 3) are then ready to be removed from the press. For the purpose of a convenient understanding of the control valve l2 the following schedule of the valve positions will be an aid:--

said coactable means and finally high pressure fluid into all of said coactable means.

3. In a system of the character described, separate sources of relatively low and high pressure fluid, main and auxiliary cylinders each having rams against which the fluid pressure is to be expanded, and a valve mechanism for controlling the flow of fluid to said cylinders comprising valve members adapted to be opened for an initial flow of low pressure fluid to either of the cylinders, means acting upon a building up of maximum low pressure thereagainst to establish communication of the high pressure fluid with Valve position 336 338 340 341 343 342 337 339 Forward Closed Closed Closed Open Closed Closed Open Open. Neutral Closed Closed Closed Open Open Open Closed Closed. Rev Op p Op Closed Closed Closed Closcd Closed.

I claim: one of the cylinders, and means acting upon a 1. In a press comprising press box and entering head units having an elongated cake compartment, a ram block heading the units, pressure means for closing the units including main cylinders centered well within the longitudinal confines of the cake line and auxiliary cylinders centered outside of the lateral confines of the cake line, rams in the respective cylinders acting on the ram block, and a reinforcing cross rib on the ram block receiving the thrust of the auxiliary rams.

2. For a. press comprising a series of press box and entering units, separate sources of relatively low and high pressure fluid, separate means coactable to move the units toward each other and thus close the press, and fluid conduits between said separate sources and separate means; a valve mechanism for controlling the flow of fluid in the conduits comprising a plurality of valve members, a plurality of cams to operate said members, and a common lay shaft carrying the cams being movable to one position to shift the valve members for a successive introduction of low pressure fluid into all of said coactable means, then high pressure fluid into a part of building up of maximum high pressure fluid thereagainst for establishing communication of said high pressure fluid with both of the cylinders.

4. A press having connected press box and entering head units terminating in a ram block at one end, a pressure cylinder containing a ram which is projectible from the cylinder by fluid pressure to close the units, an extension on the ram and means by which it is removably attached thereto, said extension contacting the ram block for said closing, a crimp lodged in the cylinder wall to pack the ram, means ordinarily operable to open the press comprising a reversing cylinder, a piston contained by the cylinder and movable therein in one direction by fluid pressure, and a rod connecting said piston with the ram block, and means for admitting pressure fluid into the other end of the reversing cylinder to recede the ram block from the pressure cylinder, thereby exposing the extension for removal so that the ram can be pushed inwardly beyond the crimp for access to the crimp.

WILSON A. WILHELM. 

